Titanatos de ferro e óxido misto de cobre e titânio como transportadores sólidos de oxigênio para utilização em processos de combustão com recirculação química
The emission of CO2 from the combustion of fossil fuels associated with the growing global demand for energy is a factor that contributes directly to global warming. In the desire to reduce emissions, as well as the severe consequences of this gas, several researchers around the world have develo...
Na minha lista:
| 主要作者: | |
|---|---|
| 其他作者: | |
| 格式: | doctoralThesis |
| 語言: | pt_BR |
| 出版: |
Universidade Federal do Rio Grande do Norte
|
| 主題: | |
| 在線閱讀: | https://repositorio.ufrn.br/handle/123456789/32471 |
| 標簽: |
添加標簽
沒有標簽, 成為第一個標記此記錄!
|
| 總結: | The emission of CO2 from the combustion of fossil fuels associated with the growing global
demand for energy is a factor that contributes directly to global warming. In the desire to reduce
emissions, as well as the severe consequences of this gas, several researchers around the world
have developed technologies that minimize these emissions and produce a cleaner CO2,
facilitating the process of CO2 capture and storage (CAC). Among the technologies, the
Chemical Looping Combustion (CLC) combustion by chemical recirculation process, which
promotes the indirect combustion of the fuel through oxygen carriers(TO), producing a
combustion where the gases are not diluted in nitrogen, obtaining a concentrated flow of CO2
facilitating their capture. Thus, this doctoral thesis aims to synthesize, characterize and test
oxygen carriers based on titanates copper and iron for use in combustion processes with
chemical looping. Oxygen transporters (TO) were synthesized from stoichiometric calculations
by the polymer precursor method (Pechini). The techniques and methodologies used were: XRay Fluorescence (XFR), X-Ray Diffraction (XRD), Mössbauer Spectroscopy (EM), Scanning
Electron Microscopy (EDS) with EDS, Programmed Temperature Reduction ), reactivity by
thermogravimetry, oxygen transport capacity (Roc) and the index rate of the reduction and
oxidation cycles. The chemical composition of each iron and copper titanate was obtained by
XFR. Through XDR with Rietveld and EM refinement, the main reactive phases were identified
as Fe2TiO5 and Fe2O3 for iron titanates and CuO for copper titanate. Through MVE-FEG with
EDS analyzed the morphology of the (TO) and the distribution of the active phases by the
surface of each one. During the TPR analysis, these active phases were submitted, respectively,
to the atmosphere of H2 and later to synthetic air and presented good capacity of reduction and
oxidation. Through the consumption of H2 used to reduce each phase, the experimental Roc of
the oxygen transporters was calculated, Obtaining 14.3% for the best iron titanate and 11.1%
for the copper titanate. The reactivity of the samples was evaluated by thermogravimetry with
methane gas (CH4) for cycles of reduction and oxidation, obtaining a conversion> 90% for iron
titanates and copper titanate with rates of 10%/min and 40%/min respectively. Due to the
structural characteristics and reactivity tests of these materials, it is concluded that both copper
titanate has the necessary requirements to be used in chemical looping (CLC) combustion
processes. |
|---|